On How to Convey Accessibility Metadata in ONIX Ahead of Publication

When questions come up about best practices for ONIX, the ONIX Implementors list (groups.io/g/onix) is an invaluable resource for the publishing community.

Recently, a member asked how to handle accessibility metadata in ONIX for titles announced long before EPUB files are available. The response below, shared with permission from author Chris Saynor (Standards Editor at EDItEUR), offers practical guidance that will be useful for anyone working to improve the quality of their accessibility metadata in compliance with the EAA. We’re sharing an adapted version of that answer here to ensure a broader audience can benefit from the insight and to highlight the ongoing value of the ONIX Implementors forum.

ONIX metadata is normally sent out initially some weeks or months prior to publication, but it is also intended to be updated as required as the publication date approaches. Even beyond publication, updates are routinely sent out to keep your business partners and the rest of the supply chain informed. Your organization will be updating your ONIX regularly, as more accurate information becomes available, and you should take the same approach with metadata relating to accessibility.

Code 08 (from list 196) is a good option if you don’t know anything about the accessibility of the title yet. It is mostly there for backlist titles that may not yet have been audited for their level of accessibility and what features they have, and I would only use it if you do not have any information. 

Otherwise, when you are looking at workflow and the commissioning of titles, what will always be a standard feature of those titles? What are you instructing your technical suppliers to do? It is good to think about ‘templates’ for each type of book you create, knowing what are going to be the standard features of your common publication types. Depending on your workflow and how your digital publications are created, there should be certain accessibility features that will always be part of certain publication types. These ‘standard’ or typical accessibility features can be put into your ONIX in advance.

If you know—or at least if you are confident that titles will conform to the WCAG 2.2 at a certain level (e.g. level AA) and will conform to the EPUB Accessibility Specification 1.1—this will mean that the titles will have certain functionalities that you will be able to put in your ONIX file right from the outset.

You could think of this like stating the physical size of a new product several months in advance. What you put in your ONIX is the size that you specify to the printers; say, 197mm high. When the physical book arrives, and turns out to be 198mm, you update the ONIX. Bookstores need the information in advance for planning purposes, even if it is only a good "estimate." The same would be true for accessibility data, even if occasionally it could prove to need a small correction when everything’s confirmed.

You might want to ask the EPUB creator to include the relevant ONIX codes inside the EPUB as well, in addition to the EPUB’s own accessibility metadata, so that when you are confirming the metadata you have both values. This example shows how they can do this in EPUB.  

Whether your supplier does this or not, there is a mapping between the EPUB/Schema accessibility metadata and from ONIX codes that can be helpful (this is the May 2025 draft of the Accessibility Properties Crosswalk; keep an eye out from BISG for the release of the final version). Once you have the more-or-less final EPUB, you can check the features of the e-book, check the embedded metadata and—if necessary—update your ONIX, too.

First, add what you know for sure from list 196 and list 81 at the outset, in your initial release of ONIX metadata. Then, add additional information or any corrections as they become available to you. It’s good to get a final confirmation of all the accessibility features when you receive the EPUB file. Make use of the fact that the ONIX is updatable in that pre-publication period. Accessibility features could even change post-publication if you make small technical alternations to the e-book master files.

You could also include in the accessibility statement—this is list 196 code 92—when you first announce a title that full accessibility information will be updated nearer to publication date. Just ensure you are clear about this and update this as it becomes clearer what accessibility features your titles have.

If you’re interested in joining the forum, the home page of the ONIX discussion forum is at groups.io/g/onix and you can subscribe to the list by sending a blank e-mail to onix+subscribe@groups.io.

If you're interested in accessibility—including compliance with the EAA and upcoming update to Title II of the ADA—consider joining BISG's Accessibility Working Group